Geneva, 22 September 2021 (dpa/MIA) - The World Health Organization (WHO) recommended much stricter limits for air pollutants on Wednesday. The WHO's new Global Air Quality Guidelines, which contain complex measurements for a range of pollutants over certain time frames, are more stringent than current European Union rules for example. The United Nations body said in a statement that studies have shown poor air quality is much more harmful to people than had long been assumed. "Air pollution is a threat to health in all countries, but it hits people in low- and middle-income countries the hardest," said WHO Director-General Tedros Adhanom Ghebreyesus. "WHO’s new Air Quality Guidelines are an evidence-based and practical tool for improving the quality of the air on which all life depends. I urge all countries and all those fighting to protect our environment to put them to use to reduce suffering and save lives." Dust particles and nitrogen dioxide (NO2) are among the most concerning pollutants. Air pollution has also played a role in coronavirus pandemic, the WHO added. People with a respiratory illness due to poor air run a greater risk than a healthy person of becoming severely ill if infected with coronavirus. Each year, the WHO estimates 7 million people worldwide die prematurely as a result of air pollution. In children, the growth of the lungs can be disturbed and asthma symptoms can increase. In adults, air pollution can help cause heart disease and strokes.